Abstract

The reasons by which a molecule might distort from an idealized high symmetry configuration (for example, D3h for the nitrate radical) in a quantum-chemical computation are well-known, but briefly reviewed here in light of considerable recent debate on the BNB molecule. The role of the pseudo-Jahn-Teller effect in such cases is emphasized, as is the ultimate relevance and proper interpretation of the title question in cases where the adiabatic potential energy surface is extremely flat.

Received 24 June 2013Accepted 12 July 2013Published online 25 July 2013

Acknowledgments:

This work was supported by the U.S. National Science Foundation (Grant CHE-1012743) and the Robert A. Welch Foundation (Grant F-1283). I am very grateful to Jürgen Gauss (Mainz), Anna Krylov (USC), Bob Cave (Harvey Mudd), Jeff Reimers (Uni Sydney), Peter Szalay (ELTE, Budapest), and Josh Baraban (MIT) for comments and useful discussions that helped to focus the content of this note.